摘要
采用MNDO方法对聚合氯化铝(PAC)中的A l13模型化合物进行了量子化学计算.结果表明:作为电子给体化学反应的活性点主要是羟基氧原子或羟基桥键氧原子,作为电子受体化学反应的活性点主要是六配位的A l.羟铝比(OH/A l)大的模型物,铝氧四面体中A l所带正电荷明显减少,表明OH/A l比大时将有更多的电子流向A l(Ⅲ).与此同时,羟桥A—lO的键级会逐渐减小,有利于PAC的水解.水解过程实际上是通过OH-的HOMO和被水解形态组分的LUMO相互作用使A—lO(H2O)键断裂形成A—lO(OH)键的过程.
Quantum chemical calculation for the model compounds of Al13 polymer in PAC were performed by means of MNDO method. Results show that the hydroxyl oxygen or the hydroxyl bridged oxygen is the electron donating reactive zone, while the six coordinated Al acts as an electron accepting center. The positive charges on the Al atom of Al-O tetrahedron17 is obviously small for the model compound with a larger ratio of OH/Al, indicating that more electrons flow to the Al （ Ⅲ ）. In addition, the bond order of hydroxyl bridged Al-O decreases as the ratio of OH/Al increases, which facilitates the hydrolysis of PAC. The hydrolysis is a process of the orbital interaction between the HOMO of OH- and the LUMO of various Al forms. As a result, the Al-O （H2O） bond breaks down and the Al-O（OH） bond comes into being.
出处
《环境化学》
CAS
CSCD
北大核心
2006年第4期395-399,共5页
Environmental Chemistry
基金
南京理工大学科技发展基金(XKF05014)
引进人才科研启动基金资助课题.
